Improved determination of selenium in serum by Zeeman atomic absorption spectrometry

Abstract

We have improved Zeeman atomic absorption spectrometric determination of selenium in serum by using an acidic solution of Ag + Cu + Mg as a matrix modifier and performing the charring step in flowing O2. Under these conditions, we could calibrate serum results with selenium standards in bovine albumin solutions. Mean analytical recovery was 98%, and the CV was 1.8% within runs, 2.9% between runs. Analysis of Reference Materials from the U.S. National Bureau of Standards (SRM 909 and RM 8419) yielded the values of 106 (SD 2.4) and 15 (SD 1.6) μg/L, respectively, in good agreement with the expected values (106 and 16, respectively). The method - being reliable and relatively simple and rapid - is suitable for use in epidemiological screenings. Mean selenium concentrations in serum sampled from 274 adults in central Italy were 90 (SD 15) μg/L. For 11-year-old children, these values were lower and showed a tendency to sex-related difference: 82 (SD 9.9) μg/L for 97 boys, 78 (SD 9.3) μg/L for 90 girls.